Re: recursive shapes in SHACL

On 3/25/15 1:35 AM, Peter F. Patel-Schneider wrote:
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> I believe that the current design of SHACL
> (https://w3c.github.io/data-shapes/shacl/) will make recursive shapes very
> problematic.
>
> Both variations in
> http://w3c.github.io/data-shapes/shacl/#sparql-AbstractValueShapePropertyConst
> raint
> do not work correctly. (Consider how the designs would work on the SHACL
> versions of the examples in
> https://lists.w3.org/Archives/Public/public-data-shapes-wg/2015Mar/0377.html.)

In that email, is the issue due to the combination of sh:valueShape with 
OrConstraint?

In the quick prototype that I published on Monday, I have changed the 
logic so that it throws an error when the same node/shape combination is 
reached for the second time within the same recursion, see line 53 of

https://github.com/HolgerKnublauch/shacl-lite/blob/master/src/org/topbraid/shacl/lite/SHACLLiteConstraintValidator.java

Would adding such a clause to the spec help? (Sorry if this was 
discussed before, I was not able to dedicate sufficient attention to the 
various ShEx-related emails on this topic).

Otherwise, how do you propose we proceed on the sh:valueShape topic?

Thanks,
Holger

>
> Does anyone have a proposal on how to handle recursive shapes that does not
> give rise to difficulties?
>
>
> peter
>
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Received on Wednesday, 25 March 2015 01:58:54 UTC